Automotive differential gearing



Feb. 16, 1937. F. H. ASAM 2,070,569

AUTOMOT IVE DIFFERENTIAL GEARING Filed Aug. 28, 1955 3 Sheets-Sheet 1 I n /,///i

T 1&

INVENTOR Fran/1 H As an:

3 :4 TTORNEY F. H. ASAM 7 2,070,569

- Feb. 16, 1937.

Filed Aug. 28, 1935 3 Sheets Sheet 2 INVENTOR Fran/iii Asa:

fiTTOR/VEY Feb. 16, 1937. s 2,070,569

AUTOMOT IVE DIFFERENTIAL GEARING Filed Aug. 28, 1935 3'Sheets-Sheet3 INVENTOR Frank .H. Asa'm 5f! .TTORNE Y El Patented Feb. 16, 1937 PATENT OFFICE 2,070,569 AUTOMOTlVE DIFFERENTIAL GEARING Frank H. Asam, Detroit,

0. Gaulrler,

Michgassignor to Francis Detroit, Mich.

Application August 28,1935, Serial No. 38,220

I 5 Claims.

This invention relates to differential gearings and particularly to improvements upon the au-' tomotive differential gearing-disclosed by the Muehl patent 1,090,082 of Mar.'10, 1914.

' In the Muehl patent, a pair of spiral gears are inate the complete loss of traction occurring wheneither of a'pair of wheels driven through an ordinary differential gearing entirely loses its tractive force.

It is the object of the invention to so form'the casing and pinions of a Muehl type of differential gearing that the strength of the pinions will be greatly increased, their accurate assembly may be more readily accomplished, and they will be more easily accessible for inspection, repairs, or replacement.

These and, various other objects the invention attains by the construction hereinafter described, and illustrated in the accompanying drawings, wherein:

Fig. 1 is a view of the improved gearing in axial sectional elevation.

Fig. 2 is a cross sectional view taken upon the line 22 of Fig. 1.

Fig. 3 is another cross section taken upon the line 3-3 of Fig. 1.

Fig. 4 is a perspective view of the casing, with its sections disassembled.

Fig. 5 is a perspective view, showing the relative positions of the gears and pinions, and indicating the spiral pitch of the teeth, and exemplifying the various directions of rotation for differential driving.

Fig. 6 is a front view of one of several washers of special design, employed in the construction.

Primarily, the invention comprises a rotative casing I, a pair of aligned live axle sections 2 and 3, oppositely entering and approximately meeting within the casing, a pair of spiral gears 4, fast on said sections in the casing, two sets of planetary spiral pinions 5, each set meshing with one of said gears, and a third set of spiral pinions 6, radially journaled in the casing and interconnecting the two first mentioned sets.

The casing comprises two end sections 1, two intermediate sections 8, and a plurality of bolts 9 extending lengthwise through the sections and rigidly clamping them together. The gears 4 are splined, one on each axle section, in chambers l jointly formed by the end and-intermediate casing sections, and are formed with hubs "ll journaled in said sections. The axes of thepinions 5 lie in the meeting planes of the end and intermediatecasing sections, which jointly form chambers l2, individually accommodating said pinions. The latter are journaled 10 tangentially of the gears 4 by stub shafts l3, in.- tegral with said pinions. The two intermediate casing sections jointly form chambers M, individually accommodating the pinions B, which have stub shafts l5 radially journaling said pinions.

The teeth of both gears and of all of the pinionsare pitched at forty-five degrees, this being essential to the desired differential action.

The end thrust incident to the spiral form of the gears is taken by hardened steel washers l6 2 a pair of which engage the hubs of each gear. Said washers are each formed with a peripheral lug H-fitting into a suitable groove I3 of the casing, and are thus held from rotation.

Rotation may be applied to the casing I in any desired manner, there being illustrated, for that purpose, a bevel gear 19 engaging an annular shoulder 20 formed on one of the casing end sections, a drive from said gear to the casing bemg established by the bolts 9.

Inoperation of the described gearing, there is, v 1 ordinarily, a balanced delivery of power to the two axle sections, and consequent elimination of any tendency to relative rotation of the pinions and gears. When differential action is required, as during turning of a vehicle equipped with the described drive gearing, the resulting relative rotation of the pinions and gears is as exemplified in Fig. 5. 40

The primary advantage of this type of differential lies in its ability to maintain a delivery of power to both axle sections, when there is a partial or complete loss of traction at one of the driven wheels. This ability arises from the fact that the pinions and gears offer quite a considerable resistance to relative rotation and jointly establishing a fulcrum, to maintain a drive to both wheels whether or not they are delivering traction.

Upon loosening the bolts 9, the casing may be opened up at any of its joints, giving access to any desired pinion or gear, without disturbance of more than one set of pinions.

The construction obviously lends itself to a 55 '2 1 e 2,070,569 A 7 sets respectively tangentially meshing with the V I rapid and compact assembly, to accurate enrespective gears, bolts rigidly and detachably' gagement of the gearing elements, and made- 'quate driving strength.

JIhe invention is presented as including all such modifications and changes as come within the scope of the following claims.

What I claim is:

1. In a differential gearing, a casing comprls- V ing two end sections and two intermediate seccasing, two'sets of spiral pinions, the respective %w .i i'i i= ig and we; n e e a tions,, andfmeans rigidly and detachably contions, an'df means fl'rigidly and; detachably connecting said sectionsya. pair of aligned driven shafts entered in opposite ends of the casing, a

pair of spiralgears fi'xed on said shafts in the sets tangentially meshing with' the" respective gears, said pinions being journaled at their inner and outer ends jointly in and jointly housed in the end and intermediate.caslngseetions and a thirdset of spiral pinions journaled jointly in the two intermediate sections of the casing and.

rid lyi ep m s ai s in m JQini r formed" by the intermediate sections, and each meshing with a pinioni of each fof the firstmentionedgfsets I, I v 2, a' differential gearing a casing comprishe'c, g saidseetionsinend to end relation, a pair of aligned driven shafts entered in opposite ends;

of theicasing, a pair or spiralgears fixed on said v shaftsinthecasing, and formed with outer hubs journaled 'i n the end sections and inner hubs. journaled inthe' intermediate sections, a set of spiral pinions tang er itially meshing with each mguntedf injaradial relation to the casing and eaehihaving; a pair of stub shafts, and each meshing with'a pinion of each'of theJfirst-menjtioned' sets, the intermediate sections of the casing; being jointly formed with chambers; indidually mi O d ti he ipi s o the third set and being further jointly formed with bear:

' ing s' for'the stub shafts of such pinions.

3. In a differential gearing, a casing comprising aplurality of sections ;apair of aligned driven shafts oppositely entered in the casing, a pair of spiral gears fixed on the shafts in the casing, two

sets of spiralpinions journaled in the casing, said 4. In a differential gearing, a casing comprising twoend sections and two intermediate sections, and means rigidly anddetaohably'c'onneoting said sections in'end toend relation; apair of aligned driven shafts entered in opposite ends'of the casing, a pair of spiral gears fixed on said shafts in the casing a set of spiral pinions tangentially meshing with each gear and each havmg a'pair ofjs'tub shafts, the casing being formed, jointly'in its end andintermediate sections; with p V chambers individually accommodating said pinions and with bearings for the stub shafts, and a third set "of spiral pinions, mounted ina radial sections qi gthe casingl being jointlyformed with chambers individually accommodating the; pin;

ions r the thir d set andz heing further jointly formed with bearings for the stub'shafts of such i pinions,

5. In a differential gearingga casing comprising two endsections and two intermediate sections,

and means rigidly and detachabl-y connecting said sections iniend, to end relation, a pair of p aligned driven shafts entered in opposite ends 01 r the. casing; a pair of spiralgearsf'fixed on said a haft in he z ca an eac hav 11 b 'journaled in one of said sections, a set of spiral pinions tangentially meshing with each gear an'd each having a pair offstuh shaitsj'the casing;

being formed, jointly in itsend andintermediate sections, with chambers individually accommodating said pinions and with'bearings for the stub shafts, n a t i d set i ri msm ntw in a radial relation to the casing and each having a pair of stub shafts an-df each meshing with a pinion oi each of thefirst-mentioned sets, the

intermediate sections of the casing being jointly formed with chambers individually accommodating the pinions of the third set and being further jointly'fo'rr'ned with bearings-for the stub shafts of such pinions. v f 7' FRANK ASAM. 

